Int J Oral Biol.  2021 Mar;46(1):15-22. 10.11620/IJOB.2021.46.1.15.

Alpha-lipoic acid protects human dopaminergic neuronal cells against hydrogen peroxide-induced cell injury by inhibiting autophagy and apoptosis

• Kang KR
• Kim JS
• Kim TH
• Seo JY
• Lim H
• Park JH
• Yang KY
• Yu SK
• Kim HJ
• Kim CS
• Chun HS
• Lee DS
• Park JC
• Kim DK

• KMID: 2514825
• DOI: http://doi.org/10.11620/IJOB.2021.46.1.15

Abstract

Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H₂O₂)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and BclxL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H₂O₂-induced cell injury by inhibiting autophagy and apoptosis.

Keyword

Alpha-lipoic acid; Autophagy; Hydrogen peroxide; Neuronal cell